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Member "memcached-1.6.15/vendor/lua/src/lmem.h" (1 Oct 2021, 3368 Bytes) of package /linux/www/memcached-1.6.15.tar.gz:


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    1 /*
    2 ** $Id: lmem.h $
    3 ** Interface to Memory Manager
    4 ** See Copyright Notice in lua.h
    5 */
    6 
    7 #ifndef lmem_h
    8 #define lmem_h
    9 
   10 
   11 #include <stddef.h>
   12 
   13 #include "llimits.h"
   14 #include "lua.h"
   15 
   16 
   17 #define luaM_error(L)   luaD_throw(L, LUA_ERRMEM)
   18 
   19 
   20 /*
   21 ** This macro tests whether it is safe to multiply 'n' by the size of
   22 ** type 't' without overflows. Because 'e' is always constant, it avoids
   23 ** the runtime division MAX_SIZET/(e).
   24 ** (The macro is somewhat complex to avoid warnings:  The 'sizeof'
   25 ** comparison avoids a runtime comparison when overflow cannot occur.
   26 ** The compiler should be able to optimize the real test by itself, but
   27 ** when it does it, it may give a warning about "comparison is always
   28 ** false due to limited range of data type"; the +1 tricks the compiler,
   29 ** avoiding this warning but also this optimization.)
   30 */
   31 #define luaM_testsize(n,e)  \
   32     (sizeof(n) >= sizeof(size_t) && cast_sizet((n)) + 1 > MAX_SIZET/(e))
   33 
   34 #define luaM_checksize(L,n,e)  \
   35     (luaM_testsize(n,e) ? luaM_toobig(L) : cast_void(0))
   36 
   37 
   38 /*
   39 ** Computes the minimum between 'n' and 'MAX_SIZET/sizeof(t)', so that
   40 ** the result is not larger than 'n' and cannot overflow a 'size_t'
   41 ** when multiplied by the size of type 't'. (Assumes that 'n' is an
   42 ** 'int' or 'unsigned int' and that 'int' is not larger than 'size_t'.)
   43 */
   44 #define luaM_limitN(n,t)  \
   45   ((cast_sizet(n) <= MAX_SIZET/sizeof(t)) ? (n) :  \
   46      cast_uint((MAX_SIZET/sizeof(t))))
   47 
   48 
   49 /*
   50 ** Arrays of chars do not need any test
   51 */
   52 #define luaM_reallocvchar(L,b,on,n)  \
   53   cast_charp(luaM_saferealloc_(L, (b), (on)*sizeof(char), (n)*sizeof(char)))
   54 
   55 #define luaM_freemem(L, b, s)   luaM_free_(L, (b), (s))
   56 #define luaM_free(L, b)     luaM_free_(L, (b), sizeof(*(b)))
   57 #define luaM_freearray(L, b, n)   luaM_free_(L, (b), (n)*sizeof(*(b)))
   58 
   59 #define luaM_new(L,t)       cast(t*, luaM_malloc_(L, sizeof(t), 0))
   60 #define luaM_newvector(L,n,t)   cast(t*, luaM_malloc_(L, (n)*sizeof(t), 0))
   61 #define luaM_newvectorchecked(L,n,t) \
   62   (luaM_checksize(L,n,sizeof(t)), luaM_newvector(L,n,t))
   63 
   64 #define luaM_newobject(L,tag,s) luaM_malloc_(L, (s), tag)
   65 
   66 #define luaM_growvector(L,v,nelems,size,t,limit,e) \
   67     ((v)=cast(t *, luaM_growaux_(L,v,nelems,&(size),sizeof(t), \
   68                          luaM_limitN(limit,t),e)))
   69 
   70 #define luaM_reallocvector(L, v,oldn,n,t) \
   71    (cast(t *, luaM_realloc_(L, v, cast_sizet(oldn) * sizeof(t), \
   72                                   cast_sizet(n) * sizeof(t))))
   73 
   74 #define luaM_shrinkvector(L,v,size,fs,t) \
   75    ((v)=cast(t *, luaM_shrinkvector_(L, v, &(size), fs, sizeof(t))))
   76 
   77 LUAI_FUNC l_noret luaM_toobig (lua_State *L);
   78 
   79 /* not to be called directly */
   80 LUAI_FUNC void *luaM_realloc_ (lua_State *L, void *block, size_t oldsize,
   81                                                           size_t size);
   82 LUAI_FUNC void *luaM_saferealloc_ (lua_State *L, void *block, size_t oldsize,
   83                                                               size_t size);
   84 LUAI_FUNC void luaM_free_ (lua_State *L, void *block, size_t osize);
   85 LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int nelems,
   86                                int *size, int size_elem, int limit,
   87                                const char *what);
   88 LUAI_FUNC void *luaM_shrinkvector_ (lua_State *L, void *block, int *nelem,
   89                                     int final_n, int size_elem);
   90 LUAI_FUNC void *luaM_malloc_ (lua_State *L, size_t size, int tag);
   91 
   92 #endif
   93